All the elements of group 15 of the periodic table have at least one isotope suitable for study by NMR spectroscopy. The magnetically active isotopes of arsenic, antimony and bismuth (75As, I¼3/2; 121Sb, I¼5/2; 123Sb, I¼7/2; 209Bi, I¼9/2;) have high abundance and relatively high sensitivity; nevertheless they have been little employed in multinuclear NMR spectroscopy owing to their high spin quantum numbers, which produce large quadrupolar moments. In fact, an efficient quadrupolar mechanism dominates their relaxation behaviour and gives rise to extremely broad resonances; this has limited the application of 75As, 121,123Sb and 209Bi NMR spectroscopy to species having a high degree of symmetry. Only a few NMR studies have been reported, and only a small amount of data, often useful in the determination of the molecular structure, is currently available.
Heteronuclear NMR Applications (As, Sb, Bi)
PETTINARI, Claudio;MARCHETTI, Fabio;RAFAIANI, Giovanni
1999-01-01
Abstract
All the elements of group 15 of the periodic table have at least one isotope suitable for study by NMR spectroscopy. The magnetically active isotopes of arsenic, antimony and bismuth (75As, I¼3/2; 121Sb, I¼5/2; 123Sb, I¼7/2; 209Bi, I¼9/2;) have high abundance and relatively high sensitivity; nevertheless they have been little employed in multinuclear NMR spectroscopy owing to their high spin quantum numbers, which produce large quadrupolar moments. In fact, an efficient quadrupolar mechanism dominates their relaxation behaviour and gives rise to extremely broad resonances; this has limited the application of 75As, 121,123Sb and 209Bi NMR spectroscopy to species having a high degree of symmetry. Only a few NMR studies have been reported, and only a small amount of data, often useful in the determination of the molecular structure, is currently available.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
